forked from Imagelibrary/rtems
197 lines
3.9 KiB
C
197 lines
3.9 KiB
C
/**
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* @file
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*
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* @ingroup bsp_clock
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*
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* @brief Clock Tick Device Driver Shell
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*/
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/*
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* COPYRIGHT (c) 1989-2012.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*/
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#include <stdlib.h>
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#include <bsp.h>
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/**
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* @defgroup bsp_clock Clock Support
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*
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* @ingroup bsp_shared
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*
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* @brief Clock support
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*
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*/
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#if CLOCK_DRIVER_USE_FAST_IDLE && CLOCK_DRIVER_ISRS_PER_TICK
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#error "clockdrv_shell.h: Fast Idle PLUS n ISRs per tick is not supported"
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#endif
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/**
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* @brief This method is rarely used so default it.
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*/
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#ifndef Clock_driver_support_find_timer
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#define Clock_driver_support_find_timer()
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#endif
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/**
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* @brief ISRs until next clock tick
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*/
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#if CLOCK_DRIVER_ISRS_PER_TICK
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volatile uint32_t Clock_driver_isrs;
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#endif
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/**
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* @brief Clock ticks since initialization
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*/
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volatile uint32_t Clock_driver_ticks;
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void Clock_exit( void );
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/**
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* @brief Clock_isr
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*
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* This is the clock tick interrupt handler.
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*
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* @param vector Vector number.
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*
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* Output parameters: NONE
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*
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* Return values: NONE
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*/
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#if defined(BSP_FEATURE_IRQ_EXTENSION) || \
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(CPU_SIMPLE_VECTORED_INTERRUPTS != TRUE)
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void Clock_isr(void *arg);
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void Clock_isr(void *arg)
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{
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#else
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rtems_isr Clock_isr(rtems_vector_number vector);
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rtems_isr Clock_isr(
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rtems_vector_number vector
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)
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{
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#endif
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/*
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* Accurate count of ISRs
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*/
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Clock_driver_ticks += 1;
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#if CLOCK_DRIVER_USE_FAST_IDLE
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do {
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rtems_clock_tick();
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} while (
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_Thread_Heir == _Thread_Executing
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&& _Thread_Executing->Start.entry_point
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== (Thread_Entry) rtems_configuration_get_idle_task()
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);
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Clock_driver_support_at_tick();
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return;
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#else
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/*
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* Do the hardware specific per-tick action.
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*
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* The counter/timer may or may not be set to automatically reload.
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*/
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Clock_driver_support_at_tick();
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#if CLOCK_DRIVER_ISRS_PER_TICK
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/*
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* The driver is multiple ISRs per clock tick.
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*/
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if ( !Clock_driver_isrs ) {
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rtems_clock_tick();
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Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK;
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}
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Clock_driver_isrs--;
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#else
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/*
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* The driver is one ISR per clock tick.
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*/
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rtems_clock_tick();
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#endif
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#endif
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}
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/**
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* @brief Clock_exit
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*
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* This routine allows the clock driver to exit by masking the interrupt and
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* disabling the clock's counter.
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*
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* Input parameters: NONE
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*
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* Output parameters: NONE
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*
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* Return values: NONE
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*
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*/
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void Clock_exit( void )
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{
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Clock_driver_support_shutdown_hardware();
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/* do not restore old vector */
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}
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/**
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* @brief Clock_initialize
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*
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* This routine initializes the clock driver.
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*
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* @param[in] major Clock device major number.
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* @param[in] minor Clock device minor number.
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* @param[in] parg Pointer to optional device driver arguments
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*
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* @retval rtems_device_driver status code
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*/
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rtems_device_driver Clock_initialize(
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rtems_device_major_number major,
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rtems_device_minor_number minor,
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void *pargp
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)
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{
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rtems_isr_entry Old_ticker;
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Clock_driver_ticks = 0;
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/*
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* Find timer -- some BSPs search buses for hardware timer
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*/
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Clock_driver_support_find_timer();
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/*
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* Install vector
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*/
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(void) Old_ticker;
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Clock_driver_support_install_isr( Clock_isr, Old_ticker );
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#if defined(Clock_driver_nanoseconds_since_last_tick)
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rtems_clock_set_nanoseconds_extension(
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Clock_driver_nanoseconds_since_last_tick
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);
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#endif
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/*
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* Now initialize the hardware that is the source of the tick ISR.
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*/
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Clock_driver_support_initialize_hardware();
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atexit( Clock_exit );
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/*
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* If we are counting ISRs per tick, then initialize the counter.
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*/
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#if CLOCK_DRIVER_ISRS_PER_TICK
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Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK_VALUE;
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#endif
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return RTEMS_SUCCESSFUL;
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}
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